WRT54GL Help...

I have currently a WRT54GL in my basement working as an AP. Now I am unable to get a signal in my bedroom on the 2nd floor on the other side of the house. I have installed a WRE54G in my bedroom but it doesn't help much. Connections keep on dropping and unable to be stream anything properly from my network in the basement. I have a spare WRT54GL and was wondering it I can just disable the wireless in my basement's WRT54GL and enable it on the second router (which I intend to keep in my kitchen area) and connect the two routers together. If it is possible, please help me out on how should I go about it as I would like to get up to medium strength in my bedroom.